1:get---返回值?cd=paypal&o_id=311&tx=9YD46560MV691781M&st=Completed&amt=16.40&cc=USD&cm=&item_number=
2:post--返回验证数据
mc_gross=16.40&invoice=300&protection_eligibility=Ineligible&payer_id=DW9GBQKK7CPT8&tax=0.00&payment_date=03:46:35 Feb 06, 2013 PST&payment_status=Completed&charset=gb2312&first_name=秋霞&mc_fee=0.86&notify_version=3.7&custom=&payer_status=verified&business=service8customer@gmail.com&quantity=1&verify_sign=A9kwfN2lWlCU5pdz5qVYDrtBJwa4A8zBjPGp-N88qr0ykgkjf363ZrMg&payer_email=customer8service@126.com&txn_id=9YD46560MV691781M&payment_type=instant&last_name=覃&receiver_email=service8customer@gmail.com&payment_fee=0.86&receiver_id=EZU9QQM7GV5N6&txn_type=web_accept&item_name=2013020628228&mc_currency=USD&item_number=&residence_country=CN&handling_amount=0.00&transaction_subject=2013020628228&payment_gross=16.40&shipping=0.00&ipn_track_id=be0afbf514c41